JP2678982B2 - Injection molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to an injection molding machine.

[0002]

2. Description of the Related Art An injection unit of an injection molding machine usually includes a front plate, a moving plate, and a rear plate from the front of a mold clamping unit. The front plate is provided with a nose portion projecting forward on the front surface, and a hopper and a heating cylinder are attached to this portion. Further, a resin introduction hole extending from the hopper to the screw fitted into the heating cylinder is formed in the nose portion.

The heating cylinder is maintained at a high temperature by a heater provided on the outer circumference in order to melt the resin inside with the action of the screw. On the other hand, in the nose part, the resin from the hopper is heated and cooled so as not to generate a bridge in the resin introduction hole, or depending on the characteristics of the resin, it is necessary to preheat the temperature and control the temperature to a predetermined temperature. There is.

However, since the nose portion is integrally formed with the plate body of the front plate and the heating cylinder is connected, the nose portion having a small heat capacity is thermally susceptible to these effects. However, it was difficult to control the temperature constant whether it was cooled or heated.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an injection molding machine capable of controlling the temperature of the nose portion of the front plate.

[0006]

[Means for Solving the Problems] A nozzle is provided at the tip.
Penetration through the cylindrical heating cylinder and the rear end of the heating cylinder
Body of front plate with through holes
And the through hole and resin that penetrate the rear end of the heating cylinder.
Form a resin introduction hole that communicates with the hopper for supplying
And a nose portion separate from the plate body. heating
Fix the rear end of the cylinder to the nose part, and
Heater on the outer periphery of the tip side of the nose part of the resin introduction hole
-Provide Warm up on the rear end side of the resin introduction hole in the nose part.
Adjusting means is provided, heating cylinder, plate body and nose
Forming at least one air gap in the joining surface between the parts
I do.

[0007]

[Function] The temperature adjusting means provided on the rear end side of the resin introduction hole in the nose portion is separate from the plate body of the front plate.
Control the temperature of the nose part of the
Material that moves to the heating cylinder through the resin introduction hole of
Preheats the material resin to the required temperature depending on the characteristics of the resin
Alternatively, cool. Also, heating cylinder, plate body
And air gap formed on the joining surface between the nose part
Between the heating cylinder, plate body and nose part
Minimal heat conduction, heating cylinder, plate body and
The nose parts are not easily affected by heat.

[0008]

1 shows a front plate 1 of an injection unit of an injection molding machine. The front plate 1 is composed of a plate body 2 and a nose portion 3, and the rear end of the heating cylinder 4 is attached to the nose portion 3. The plate body 2 has a heating cylinder 4 in the center.
A through hole 5 through which the rear end of the tie bar 6 penetrates ;
Is connected to a rear plate (not shown).
Reference numeral 7 denotes a cover.

The nose portion 3 is a member separate from the plate main body 2 and has a penetrating hole through which the rear end of the heating cylinder 4 penetrates in the center.
A through hole 8 is provided, and a resin introducing hole 9 that penetrates in the radial direction is provided at an upper portion. The flow path 10 of the nose portion 3 in which the temperature adjusting liquid flows is formed on the rear end side of the resin introducing hole 9 communicating with the hopper (not shown) (FIG. 1). The flow path 10 through which the temperature control liquid flows is a heating means when preheating the nose portion 3. The heating cylinder 4 has a resin introduction hole 9 in the nose portion 3 as well as a conventionally known one.
Also equipped with a heater (not shown) on the outer circumference on the tip side,
Both the inside provided with a screw 11, the heating cylinder 4
The rear end of the nose portion 3 and the play hole
It is fitted into the through hole 5 of the main body 2 .

In the nose portion 3, a positioning ring 12 for centering is screwed to an annular central portion on the rear surface, and then this is formed on the front surface of the plate body 2 through hole 5.
Is fitted into an annular positioning groove 13 formed around
The nose portion 3 is fixed to the plate body 2 by bolts 14 that reach the plate body 2 from the front surface. At this time, the rear surface of the nose portion 3 and the front surface of the plate body 2 directly contact with each other at the annular raised portion 15 formed on the outer periphery of the positioning groove 13, but the rear surface of the nose portion 3 and the plate facing the rear surface. An air gap 16a is formed between the main body 2 and the front surface.
Is formed in front of the positioning ring 12 and the plate body 2.
An air gap 16b is formed between the surface and the surface . A positioning pin or the like may be used instead of the positioning ring 12.

In the heating cylinder 4, first, the flange 17 is attached to the stepped portion of the rear end by screwing, and then the rear end of the heating cylinder 4 is a through hole of the nose portion 3.
8 and the through holes 5 of the plate body 2 and fixed to the plate body 2 by bolts 18 that penetrate the nose portion 3 from the front side of the flange 17 and reach the plate body 2. At this time, the rear surface of the flange 17 and the front surface of the nose portion 3 have a raised portion 19 formed on the outer periphery of the nose portion 3.
Contact the front of the nose part 3 and face it.
An air gap 16c is formed between the rear surface of the flange 17 and the rear surface . Further, an air gap 16d is formed between the inner peripheral surface of the through hole 8 and the outer peripheral surface of the heating cylinder 4 in the nose portion 3 and between the inner peripheral surface of the through hole 5 and the outer peripheral surface of the heating cylinder 4 in the plate body 2. Is formed.

The resin introduction hole 9 of the nose portion 3 is machined when this is a separate member attached to the plate body 2. The processing is grinding, plating or lining as required. In some cases, the nose portion 3 once assembled to the plate body 2 can be removed and subjected to necessary processing. In this case, since it is conventionally integrally formed with the plate body of the front plate, it is not necessary to handle the entire front plate having a complicated shape and a large weight, and the resin introduction hole for the nose portion 3 can be easily processed.

At the time of injection molding, the heating cylinder 4 is heated by the heater, and the temperature control liquid is circulated in the flow passage 10 of the nose portion 3. The nose portion 3 is heated by the heat from the heating cylinder 4 and is cooled by the heat conduction to the plate body 2 and the flange 17 , but the temperature is controlled to a predetermined temperature by the temperature adjusting liquid passing through the flow path 10. . Also, at this time,
In this embodiment, the heating cylinder 4, nose portion 3,
Since there is an air gap 16 (a to d) on the joint surface between the plate body 2 and the flange 17 and the heat conduction between these members is small, the heating cylinder 4, the nose.
The part 3, the plate body 2 and the flange 17 are heat shadowed to each other.
A heating cylinder for the nose part 3
4. The thermal influence from the plate body 2 and the flange 17 is small, and it is easy to control the temperature by the temperature control liquid that passes through the flow path 10 of the nose portion 3 . The above is one embodiment, and the invention of the present application is not limited to the illustrated specific configuration.

[0014]

The temperature control means controls the temperature of the nose portion.
So, from the hopper, pass through the resin introduction hole in the nose part.
The molding material resin that moves to the heating cylinder is transferred by the temperature control means.
Preheated to the required temperature according to the resin characteristics or
Can be cooled and the nose part is separate from the plate body
As it is a body, only the nose part can be easily temperature controlled independently.
A resin introduction hole in the nose part that is separate from the plate body.
It is necessary for the wall surface of the resin introduction hole in the nose part, etc.
Depending on the situation, additional processing such as plating can be easily performed.
You. Also, heating cylinder, plate body and nose part
Since there is an air gap in the bonding surface between the
The heat transfer between the chassis, the plate body and the nose part
The heating cylinder,
The plate body and nose part are not affected by heat from each other.
Heating cylinder and plate body for the nose part
Since the thermal effect from the
Easy temperature control by

[Brief description of the drawings]

FIG. 1 is a front view shown in cross section.

[Explanation of symbols]

Reference Signs List 1 front plate 2 plate body 3 nose portion 4 heating cylinder 5 through hole 6 tie bar 7 cover 8 through hole 9 resin introduction hole 10 flow path 11 screw 12 positioning ring 13 positioning groove 14 bolt 15 raised portion 16 air gap 17 flange 18 bolt

Claims (1)

(57) [Claims] 1. A cylindrical heating cylinder having a nozzle at its tip and a through hole penetrating the rear end of the heating cylinder.
The plate body of the front plate on which the
Pre resin introduction hole communicating with the hopper for supplying the through-hole and the resin through the rear end portion of the cylinder is formed
The heating cylinder has a nose part that is separate from the main body, and the rear end of the heating cylinder is fixed to the nose part.
In an injection molding machine in which a heater is provided on the outer periphery on the tip side of the resin introduction hole of the nose part , a temperature adjusting means is provided on the rear end side of the resin introduction hole of the nose part , and the heating cylinder, plug
Air gap on the mating surface between the rate body and the nose part
An injection molding machine, wherein at least one is formed .